Author: Dev

How to list all tables from a schema of Oracle database To list all tables from a schema of Oracle database you can use tables: USER_TABLES, USER_ALL_TABLES, TABS, ALL_TABLES, DBA_TABLES, USER_OBJECTS. Certain tables require privileges from the database DBA. The most used tables are USER_TABLES and USER_OBJECTS. Examples SELECT * FROM USER_TABLES; SELECT * FROM…(Continue Reading)

Data Dictionary is a part of Oracle database. Data Dictionary is a read-only set of tables that provides information about the database. The data dictionary is structured in tables and views. A data dictionary contains: The definitions of all schema objects in the database (tables, views, indexes, clusters, synonyms, sequences, procedures, functions, packages, triggers). Informations…(Continue Reading)

ORA-04091: table is mutating, trigger/function may not see it Oracle PL/SQL error message: ORA-04091: table is mutating, trigger/function may not see it Cause: A trigger (or a user defined PL/SQL function that is referenced in this statement) attempted to look at (or modify) a table that was in the middle of being modified by the…(Continue Reading)

ORA-06503: PL/SQL: Function returned without value Oracle PL/SQL error message: ORA-06503: PL/SQL: Function returned without value Cause: A call to PL/SQL function completed, but no RETURN statement was executed. Solution: Rewrite PL/SQL function, making sure that it always returns a value of a proper type. Example: create or replace function get_name(p_id number) return varchar2 as…(Continue Reading)

Error Messages Page 2 ORA-00913: too many values ORA-00917: missing comma ORA-00918: column ambiguously defined ORA-00926: missing VALUES keyword ORA-00933: SQL command not properly ended ORA-00936: missing expression ORA-00998: must name this expression with a column alias ORA-00999: invalid view name ORA-01001: invalid cursor ORA-01017 invalid username/password; logon denied ORA-01017: invalid username/password logon denied ORA-01031…(Continue Reading)